JsonArray.contains(JsonObject / JsonArray) returns false, in case JsonObject / JsonArray is represented as Map / List internally

[kristian]

If you want to check whether a JsonArray contains a certain JsonObject or other JsonArray you may wrongly assume you can use the contains method. However as sometimes a JsonObject / JsonArray is represented as a Map or List in the internal JsonArray list, contains might return false even though semantically it should return true. Minimal reproducible example:

JsonArray jsonArray = new JsonArray("[{\"foo\":\"bar\"}]");
System.out.println(jsonArray.contains(new JsonObject().put("foo", "bar"))); // false

System.out.println(jsonArray.contains(new JsonObject().put("foo", "bar").getMap())); // true
System.out.println(jsonArray.stream().anyMatch(obj -> obj.equals(new JsonObject().put("foo", "bar")))); // true

My assumption would be that the contains function behaves similarly to the contains function of the List interface, where it is documented that it returns true in case:

Returns true if this list contains the specified element. More formally, returns true if and only if this list contains at least one element e such that (o==null ? e==null : o.equals(e)).

Which is not the case for the contains function of the JsonArray. So I would suggest this should be either treated as a bug, or the behaviour should be documented in the JavaDoc of the contains function.

[tsegismont]

Thanks for detailed report @kristian . Would you like to propose a PR ?

[kristian]

Sure @tsegismont, I can create a PR. Thanks for the quick reply!

[kristian]

@tsegismont PR #5398 👍